One concern in electronics design is space savings. Using less space for component(s) leads to a smaller footprint for the overall design of a product or product component. This permits an electronics product to be made smaller or more components may be added to the original footprint.
This is especially relevant to circuit board components where space is at a premium. Any conservation measures that can be applied to printed circuit boards (PCBs) are considered extremely valuable because of the resulting decreased footprint or increased density of circuit board components. Increased density yields more electronics components per unit area and that translates into increased functionality for the electronics product.
One particular electronics product that strives to decrease its physical size and increase its functional capabilities is the mobile telephone. Today's mobile telephones are sleek, ultra-thin, and ultra-lite designs when compared to the mobile telephones of a few years ago. Advancements in printed circuit board (PCB) component mounting techniques have contributed greatly to these new designs.
Finding ways to achieve additional space savings for mobile telephone designs is desirable to vendors and consumers alike. One area of mobile telephone design that impinges on usable printed circuit board (PCB) space is the keypad. Current mobile telephone keypads typically contain electrical contacts for the keys on the underside of each key. The keys are pressed down into contact with corresponding electrodes on a printed circuit. This severely limits the printed circuit board (PCB) space available for other components directly under the keypad.
The same limitations described for mobile telephone keypads also apply to other electronics devices that require a keypad or keyboard of some sort. Such other products may include, landline telephones, cordless telephones, personal digital assistants (PDAs), integrated computer products, computer laptops, pagers, etc.
What is needed is a keypad device that does not require key contacts to be mounted on a printed circuit board (PCB) in order to be detected.